19. The best job is _______ which uses your skills in doing something together with your interest in the subject.

A．something

B．the one

C．one

D．it

湿邪致病，病程长，缠绵难愈，其原因是（）。

A.湿为阴邪，阻遏气机

B.湿邪伤阳

C.湿性黏滞

D.湿性重浊

E.湿性趋下